Scrapy FormRequest，试图发送一个post request (FormRequest)与货币变化的for

Question

我一直在尝试抓取以下网站但随着货币从左上角的设置形式改为"SAR"，我试着发送这样一个粗糙的请求:

r = Request(url='https://www.mooda.com/en/', cookies=[{'name': 'currency',
                                        'value': 'SAR',
                                        'domain': '.www.mooda.com',
                                        'path': '/'}, {'name':'country','value':'SA','domain': '.www.mooda.com','path':'/'}],dont_filter=True)

，我仍然得到EG的价格

In [10]: response.css('.price').xpath('text()').extract()
Out[10]: 
[u'1,957 EGxa3',
 u'3,736 EGxa3',
 u'2,802 EGxa3',
 u'10,380 EGxa3',
 u'1,823 EGxa3']

我也试图发送一个post请求与指定的表单数据像这样:

from scrapy.http.request.form import FormRequest
url = 'https://www.mooda.com/en/'
r = FormRequest(url=url,formdata={'selectCurrency':'https://www.mooda.com/en/directory/currency/switch/currency/SAR/uenc/aHR0cHM6Ly93d3cubW9vZGEuY29tL2VuLw,,/'})
fetch(r)

仍然不会工作，也尝试使用FormRequest.from_response()，但它永远不会工作，我真的很喜欢一些建议，我新的scrapy表单请求，如果有人可以帮助，我会很感激

Answer 1

这都是关于前端 cookie的，我将首先向您展示如何使用请求来实现它，逻辑将与Scrapy完全相同:

head = {        "User-Agent": "Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:47.0) Gecko/20100101 Firefox/47.0"}
#
import requests
from bs4 import BeautifulSoup
with requests.Session() as s:
    soup = BeautifulSoup(s.get("https://www.mooda.com/en/").content)
    r2 = s.get(soup.select_one("#selectCurrency option[value*=SAR]")["value"])
    r = s.get("https://www.mooda.com/en/", params={"currency": "sar"}, headers=head, cookies=dict(r2.cookies.items()))
    soup2 = BeautifulSoup(r.content)
    print(soup2.select_one(".price").text)

您需要向id为selectCurrency的选项下的url发出请求，然后在您向https://www.mooda.com/en?currency=sar发出请求时传递返回的cookie。没有帖子，都是get请求，但是get的前端 cookie是必不可少的。

如果我们运行代码，你会看到它确实给了我们正确的数据:

In [9]: with requests.Session() as s:
   ...:         soup = BeautifulSoup(s.get("https://www.mooda.com/en/").content,"lxml")
   ...:         r2 = s.get(soup.select_one("#selectCurrency option[value*=SAR]")["value"])
   ...:         r = s.get("https://www.mooda.com/en/", params={"currency": "sar"}, headers=head, cookies=dict(r2.cookies.items()))
   ...:         soup2 = BeautifulSoup(r.content,"lxml")
   ...:         print(soup2.select_one(".price").text)
   ...:     
825 SR

使用scrapy:

class S(Spider):
    name = "foo"
    allowed_domains = ["www.mooda.com"]
    start_urls = ["https://www.mooda.com/en"]
    def parse(self, resp):
        curr = resp.css("#selectCurrency option[value*='SAR']::attr(value)").extract_first()
        return Request(curr, callback=self.parse2)
    def parse2(self, resp):
        print( resp.headers.getlist('Set-Cookie'))
        return Request("https://www.mooda.com/en?currency=sar",cookies=cookies, callback=self.parse3)
    def parse3(self, resp):
        print(resp.css('.price').xpath('text()').extract())

如果你运行，它会给你:

['frontend=c95er9h1at2srhtqu5rkfo13g0; expires=Wed, 28-Jun-2017 08:56:08 GMT; path=/; domain=www.mooda.com', 'currency=SAR; expires=Wed, 28-Jun-2017 08:56:08 GMT; path=/; domain=www.mooda.com']

[u'825 SR', u'1,575 SR', u'1,181 SR', u'4,377 SR', u'769 SR']

get to current不返回任何东西，它只是设置cookie